linux/drivers/net/wireless/ath/ath9k/debug_sta.c
Toke Høiland-Jørgensen 50f08edf98 ath9k: Switch to using mac80211 intermediate software queues.
This switches ath9k over to using the mac80211 intermediate software
queueing mechanism for data packets. It removes the queueing inside the
driver, except for the retry queue, and instead pulls from mac80211 when
a packet is needed. The retry queue is used to store a packet that was
pulled but can't be sent immediately.

The old code path in ath_tx_start that would queue packets has been
removed completely, as has the qlen limit tunables (since there's no
longer a queue in the driver to limit).

The mac80211 intermediate software queues offer significant latency
reductions, and this patch allows ath9k to realise them. The exact gains
from this varies with the test scenario, but in an access point scenario
we have seen latency reductions ranging from 1/3 to as much as an order
of magnitude. We also achieve slightly better aggregation.

Median latency (ping) figures with this patch applied at the access point,
with two high-rate stations and one low-rate station (HT20 5Ghz), running
a Flent rtt_fair_var_up test with one TCP flow and one ping flow going to
each station:

                                 Fast station        Slow station
Default pfifo_fast qdisc:            430.4 ms            638.7 ms
fq_codel qdisc on iface:              35.5 ms            211.8 ms
This patch set:                       22.4 ms             38.2 ms

Median aggregation sizes over the same test:

Default pfifo_fast qdisc:            9.5 pkts            1.9 pkts
fq_codel qdisc on iface:            11.2 pkts            1.9 pkts
This patch set:                     13.9 pkts            1.9 pkts

This patch is based on Tim's original patch set, but reworked quite
thoroughly.

Cc: Tim Shepard <shep@alum.mit.edu>
Cc: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
2016-11-15 17:00:04 +02:00

255 lines
6.4 KiB
C

/*
* Copyright (c) 2013 Qualcomm Atheros, Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "ath9k.h"
/*************/
/* node_aggr */
/*************/
static ssize_t read_file_node_aggr(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
struct ath_node *an = file->private_data;
struct ath_softc *sc = an->sc;
struct ath_atx_tid *tid;
struct ath_txq *txq;
u32 len = 0, size = 4096;
char *buf;
size_t retval;
int tidno;
buf = kzalloc(size, GFP_KERNEL);
if (buf == NULL)
return -ENOMEM;
if (!an->sta->ht_cap.ht_supported) {
len = scnprintf(buf, size, "%s\n",
"HT not supported");
goto exit;
}
len = scnprintf(buf, size, "Max-AMPDU: %d\n",
an->maxampdu);
len += scnprintf(buf + len, size - len, "MPDU Density: %d\n\n",
an->mpdudensity);
len += scnprintf(buf + len, size - len,
"\n%3s%11s%10s%10s%10s%10s%9s%6s%8s\n",
"TID", "SEQ_START", "SEQ_NEXT", "BAW_SIZE",
"BAW_HEAD", "BAW_TAIL", "BAR_IDX", "SCHED", "PAUSED");
for (tidno = 0; tidno < IEEE80211_NUM_TIDS; tidno++) {
tid = ath_node_to_tid(an, tidno);
txq = tid->txq;
ath_txq_lock(sc, txq);
if (tid->active) {
len += scnprintf(buf + len, size - len,
"%3d%11d%10d%10d%10d%10d%9d%6d\n",
tid->tidno,
tid->seq_start,
tid->seq_next,
tid->baw_size,
tid->baw_head,
tid->baw_tail,
tid->bar_index,
!list_empty(&tid->list));
}
ath_txq_unlock(sc, txq);
}
exit:
retval = simple_read_from_buffer(user_buf, count, ppos, buf, len);
kfree(buf);
return retval;
}
static const struct file_operations fops_node_aggr = {
.read = read_file_node_aggr,
.open = simple_open,
.owner = THIS_MODULE,
.llseek = default_llseek,
};
/*************/
/* node_recv */
/*************/
void ath_debug_rate_stats(struct ath_softc *sc,
struct ath_rx_status *rs,
struct sk_buff *skb)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct ath_hw *ah = sc->sc_ah;
struct ieee80211_rx_status *rxs;
struct ath_rx_rate_stats *rstats;
struct ieee80211_sta *sta;
struct ath_node *an;
if (!ieee80211_is_data(hdr->frame_control))
return;
rcu_read_lock();
sta = ieee80211_find_sta_by_ifaddr(sc->hw, hdr->addr2, NULL);
if (!sta)
goto exit;
an = (struct ath_node *) sta->drv_priv;
rstats = &an->rx_rate_stats;
rxs = IEEE80211_SKB_RXCB(skb);
if (IS_HT_RATE(rs->rs_rate)) {
if (rxs->rate_idx >= ARRAY_SIZE(rstats->ht_stats))
goto exit;
if (rxs->flag & RX_FLAG_40MHZ)
rstats->ht_stats[rxs->rate_idx].ht40_cnt++;
else
rstats->ht_stats[rxs->rate_idx].ht20_cnt++;
if (rxs->flag & RX_FLAG_SHORT_GI)
rstats->ht_stats[rxs->rate_idx].sgi_cnt++;
else
rstats->ht_stats[rxs->rate_idx].lgi_cnt++;
goto exit;
}
if (IS_CCK_RATE(rs->rs_rate)) {
if (rxs->flag & RX_FLAG_SHORTPRE)
rstats->cck_stats[rxs->rate_idx].cck_sp_cnt++;
else
rstats->cck_stats[rxs->rate_idx].cck_lp_cnt++;
goto exit;
}
if (IS_OFDM_RATE(rs->rs_rate)) {
if (ah->curchan->chan->band == NL80211_BAND_2GHZ)
rstats->ofdm_stats[rxs->rate_idx - 4].ofdm_cnt++;
else
rstats->ofdm_stats[rxs->rate_idx].ofdm_cnt++;
}
exit:
rcu_read_unlock();
}
#define PRINT_CCK_RATE(str, i, sp) \
do { \
len += scnprintf(buf + len, size - len, \
"%11s : %10u\n", \
str, \
(sp) ? rstats->cck_stats[i].cck_sp_cnt : \
rstats->cck_stats[i].cck_lp_cnt); \
} while (0)
#define PRINT_OFDM_RATE(str, i) \
do { \
len += scnprintf(buf + len, size - len, \
"%11s : %10u\n", \
str, \
rstats->ofdm_stats[i].ofdm_cnt); \
} while (0)
static ssize_t read_file_node_recv(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
struct ath_node *an = file->private_data;
struct ath_softc *sc = an->sc;
struct ath_hw *ah = sc->sc_ah;
struct ath_rx_rate_stats *rstats;
struct ieee80211_sta *sta = an->sta;
enum nl80211_band band;
u32 len = 0, size = 4096;
char *buf;
size_t retval;
int i;
buf = kzalloc(size, GFP_KERNEL);
if (buf == NULL)
return -ENOMEM;
band = ah->curchan->chan->band;
rstats = &an->rx_rate_stats;
if (!sta->ht_cap.ht_supported)
goto legacy;
len += scnprintf(buf + len, size - len,
"%24s%10s%10s%10s\n",
"HT20", "HT40", "SGI", "LGI");
for (i = 0; i < 24; i++) {
len += scnprintf(buf + len, size - len,
"%8s%3u : %10u%10u%10u%10u\n",
"MCS", i,
rstats->ht_stats[i].ht20_cnt,
rstats->ht_stats[i].ht40_cnt,
rstats->ht_stats[i].sgi_cnt,
rstats->ht_stats[i].lgi_cnt);
}
len += scnprintf(buf + len, size - len, "\n");
legacy:
if (band == NL80211_BAND_2GHZ) {
PRINT_CCK_RATE("CCK-1M/LP", 0, false);
PRINT_CCK_RATE("CCK-2M/LP", 1, false);
PRINT_CCK_RATE("CCK-5.5M/LP", 2, false);
PRINT_CCK_RATE("CCK-11M/LP", 3, false);
PRINT_CCK_RATE("CCK-2M/SP", 1, true);
PRINT_CCK_RATE("CCK-5.5M/SP", 2, true);
PRINT_CCK_RATE("CCK-11M/SP", 3, true);
}
PRINT_OFDM_RATE("OFDM-6M", 0);
PRINT_OFDM_RATE("OFDM-9M", 1);
PRINT_OFDM_RATE("OFDM-12M", 2);
PRINT_OFDM_RATE("OFDM-18M", 3);
PRINT_OFDM_RATE("OFDM-24M", 4);
PRINT_OFDM_RATE("OFDM-36M", 5);
PRINT_OFDM_RATE("OFDM-48M", 6);
PRINT_OFDM_RATE("OFDM-54M", 7);
retval = simple_read_from_buffer(user_buf, count, ppos, buf, len);
kfree(buf);
return retval;
}
#undef PRINT_OFDM_RATE
#undef PRINT_CCK_RATE
static const struct file_operations fops_node_recv = {
.read = read_file_node_recv,
.open = simple_open,
.owner = THIS_MODULE,
.llseek = default_llseek,
};
void ath9k_sta_add_debugfs(struct ieee80211_hw *hw,
struct ieee80211_vif *vif,
struct ieee80211_sta *sta,
struct dentry *dir)
{
struct ath_node *an = (struct ath_node *)sta->drv_priv;
debugfs_create_file("node_aggr", S_IRUGO, dir, an, &fops_node_aggr);
debugfs_create_file("node_recv", S_IRUGO, dir, an, &fops_node_recv);
}